Page 198 of 480

197 Controls in detail
Retractable hardtop
Pull up on the hardtop switch as indi-
cated by the arrow until the hardtop is
completely lowered into its trunk stor-
age compartment and the indicator
lamp in the hardtop switch goes out.
The multifunction display will briefly
show the message K
in operation
.Closing the retractable hardtop with
the switch
Before pressing the hardtop switch, you
must make sure
the parking brake is engaged
(page 51)
the luggage cover is closed
(page 196)
the trunk lid is closed
the ignition is switched on
Press the hardtop switch as indicated
by the arrow until the hardtop is com-
pletely closed and locked and the indi-
cator lamp in the hardtop switch goes
out.
The multifunction display will briefly
show the message
+
in operation
.
iBe sure that the roof is dry before you
open it. Otherwise water may enter the
trunk interior.
Warning!
G
If the retractable hardtop is not fully opened
or closed, a warning will sound after 15 sec-
onds, pressure in the hardtop’s hydraulic
system will drop and the hardtop will lower.
Be sure to keep the hardtop switch pulled or
pressed until the hardtop is fully opened or
closed. The hydraulic pump will then shut
off.
To prevent possible accidents, drive the ve-
hicle only with the hardtop either completely
closed and locked, or fully lowered into its
storage compartment.
Page 205 of 480

204 Controls in detailDriving systemsThe driving systems of your vehicle are de-
scribed on the following pages:
Cruise control and Distronic*, with
which the vehicle can maintain a preset
speed
ABC with vehicle level control systems,
with which you can change vehicle sus-
pension characteristics
Parktronic*, which assists the driver
during parking maneuvers
For information on the BAS, ABS, and
ESP®, see “Driving safety systems”
(
page 82).
Cruise control
The cruise control automatically maintains
the speed you set for your vehicle.
Use of cruise control is recommended for
driving at a constant speed for extended
periods of time. Cruise control can be set
at any speed above 20 mph (30 km/h).
The cruise control function is operated by
means of the cruise control lever.
The cruise control lever is the uppermost
lever found on the left-hand side of the
steering column (
page 22).
Warning!
G
The cruise control is a convenience system
designed to assist the driver during vehicle
operation. The driver is and must remain at
all times responsible for the vehicle speed
and for safe brake operation.
Only use the cruise control if the road,
traffic, and weather conditions make it ad-
visable to travel at a steady speed.
The use of cruise control can be danger-
ous on winding roads or in heavy traffic
because conditions do not allow safe
driving at a steady speed.
The use of cruise control can be danger-
ous on slippery roads. Rapid changes in
tire traction can result in wheel spin and
loss of control.
Deactivate the cruise control when driv-
ing in fog.
The “Resume” function should only be oper-
ated if the driver is fully aware of the previ-
ously set speed and wishes to resume this
particular preset speed.
Page 207 of 480

206 Controls in detailDriving systems
Setting a higher speed
Lift the cruise control in direction of
arrow1 (
page 205) and hold it
there until the desired speed is
reached.
Release the cruise control lever.
The new speed is set.
Setting a lower speed
Depress the cruise control in direction
of arrow2 (
page 205) and hold it
there until the desired speed is
reached.
Release the cruise control lever.
The new speed is set.
iThe cruise control switches off auto-
matically if
you step on the brake pedal
you depress the parking brake
pedal
The cruise control also switches off au-
tomatically when
the vehicle speed is below
20 mph (30 km/h) (
page 204)
the ESP
® is in operation or switched
off with the ESP
® switch
(
page 86)
you move the gear selector lever to
positionN while driving
An acoustic warning sounds and the
message
CC Off
appears in the multi-
function display for approximately
5 seconds.
iDepressing the accelerator pedal does
not deactivate the cruise control. After
brief acceleration (e.g. for passing), the
cruise control will resume the last
speed set.iThe last stored speed is canceled when
you turn off the engine.!Moving the gear selector lever to
positionN while driving also cancels
cruise control. However, the gear se-
lector lever should not be moved to
positionN while driving except to coast
when the vehicle is in danger of skid-
ding (e.g. on icy roads).
iWhen you use the cruise control lever
to decelerate, the brake system will au-
tomatically brake the vehicle if the en-
gine’s braking power does not brake
the vehicle sufficiently.
Page 213 of 480

212 Controls in detailDriving systemsCruise control lever
The Distronic system is operated by means
of the cruise control lever.
The cruise control lever is the uppermost
lever found on the left-hand side of the
steering column.
1Set current or higher speed
2Set current or lower speed
3Deactivate Distronic
4Resume at last set speedActivating Distronic
You can activate Distronic if
the vehicle speed is within a certain
range. The range is between
20 mph (30 km/h) and 110 mph
(180 km/h).
the ESP
® is activated (
page 85).
When Distronic is activated the speedome-
ter display will show a message such as
DTR 60 mph
.
If Distronic is deactivated, the speedome-
ter display will show the message
DTR --- mph
.
In the following cases you cannot activate
Distronic:
up to 2 minutes after starting the en-
gine
when you brake
if you have set the parking brake
if the gear selector lever is in
positionP, R, or N.
if the ESP
® is switched off1Set speed
2White DTR indicator lamp E
Setting the current speed
Accelerate or decelerate to the desired
speed.iThe vehicle speed displayed on the
speedometer can briefly vary from the
speed setting on the Distronic system.
Page 215 of 480

214 Controls in detailDriving systemsSetting to last stored speed
(“Resume” function)
Briefly tip the cruise control lever in
direction of arrow4 (
page 212).
Distronic is set to the last stored
speed.
Remove your foot from the accelerator
pedal.Deactivating Distronic
There are several ways to deactivate the
Distronic system:
Briefly tip the cruise control lever in
direction of arrow3 (
page 212).
or
Step on the brake pedal.
Distronic will be deactivated. The last
speed set will be stored into memory.Distronic deactivates automatically when
you set the parking brake
you drive slower than
20 mph (30 km/h) (
page 212)
the ESP
® is active (
page 85) or you
deactivate the ESP
®
You move the gear selector lever into
positionN.
A signal will sound. The
DTR off
mes-
sage appears in the speedometer dis-
play for approximately 5 seconds.
Warning!
G
The speed stored in memory should only be
set again if prevailing road conditions per-
mit. Possible acceleration or deceleration
differences arising from returning to the pre-
set speed could endanger yourself and oth-
ers.
iThe last stored speed is deleted when
you turn off the engine.
Warning!
G
Distronic switches off and releases the
brakes when the vehicle decelerates below
the minimum speed of 25 mph (40 km / h)
or, depending on vehicle production date,
20 mph (30 km/h) by operation of the sys-
tem. At that time the driver must apply the
brakes in order to reduce vehicle speed fur-
ther or bring it to a stop.
Page 224 of 480

223 Controls in detail
Driving systems
Parktronic* (Parking assist)
The Parktronic system is an electronic aid
designed to assist the driver during park-
ing maneuvers. It visually and audibly indi-
cates the relative distance between the
vehicle and an obstacle.
The Parktronic system is automatically ac-
tivated when you switch on the ignition, re-
lease the parking brake, or place the gear
selector lever in position D, R, or N. The
Parktronic system deactivates at speeds
above 11 mph (18 km/h). At lower speeds
the Parktronic system turns on again.
The Parktronic system also deactivates
when you place the gear selector lever in
position P or depress the brake pedal.The Parktronic system monitors the sur-
roundings of your vehicle with six sensors
in the front bumper and four sensors in the
rear bumper.
1Sensors in the front bumperWarning!
G
Parktronic is a supplemental system. It is
not intended to, nor does it replace, the
need for extreme care. The responsibility
during parking and other critical maneuvers
always rests with the driver.
Special attention must be paid to objects
with smooth surfaces or low silhouettes
(e.g. trailer couplings, painted posts, or road
curbs). Such objects may not be detected by
the system and can damage the vehicle.
The operational function of the Parktronic
system can be affected by dirty sensors, es-
pecially at times of snow and ice. See
“Cleaning the Parktronic* system sensors”
(page 326).
Interference caused by other ultrasonic sig-
nals (e.g. working jackhammers, car wash,
or the air brakes of trucks) can cause the
system to send erratic indications, and
should be taken into consideration.
Warning!
G
Make sure no persons or animals are in the
area in which you are maneuvering. Other-
wise you run the risk of causing injury.
Page 225 of 480
224 Controls in detailDriving systemsRange of the sensors
To function properly, the sensors must be
free of dirt, ice snow and slush. Clean the
sensors regularly, being careful not to
scratch or damage the sensors, see
“Cleaning the Parktronic system* sensors”
(page 326).
Front sensors
Rear sensors
Center
approx. 40 in (100 cm)
Corners
approx. 24 in (60 cm)
Center
approx. 48 in (120 cm)
Corners
approx. 32 in (80 cm)
!During parking maneuvers, pay special
attention to objects located above or
below the height of the sensors (e.g.
planters or trailer hitches).
The Parktronic system will not detect
such objects at close range and dam-
age to your vehicle or the object may
result.
Ultrasonic signals from outside sourc-
es (e.g. truck air brakes, car wash, or
jackhammers) may impair the opera-
tion of the Parktronic system.
Page 227 of 480

226 Controls in detailDriving systemsAs your vehicle approaches an object, one
or more distance segments will illuminate,
depending on the distance. When the
eighth distance segment illuminates, you
have reached the minimum distance.
Front area: An intermittent acoustic
warning will sound as the first red dis-
tance segment illuminates and a con-
stant acoustic warning lasting a
maximum of two seconds will sound for
the second distance segment. The sig-
nal is canceled when the gear selector
lever is placed in position P or the park-
ing brake is set.
Rear area: An intermittent acoustic
warning will sound when the first dis-
tance segment illuminates. This signal
quickens with each additional distance
segment lit. When the eighth distance
segment illuminates, the acoustic
warning becomes a constant signal.
The signal is canceled when the gear
selector lever is placed in positionD
orP or the parking brake is set.Switching the Parktronic system
on/off
You can switch off the Parktronic system
manually.
The Parktronic switch is located in the low-
er part of the center console (
page 30).
1Parktronic switch
2Indicator lampSwitching off the Parktronic system
Press Parktronic switch1.
Indicator lamp2 comes on.
Switching on the Parktronic system
Press Parktronic switch1 again.
Indicator lamp2 goes out.iThe Parktronic system switches on au-
tomatically when you switch on the ig-
nition (
page 36).